OK... when I put my ZF in, I installed it with the SMF and clutch that came with the tranny... looked like a stock IDI/T19 flywheel and some kind of clutch/PP combo that bolted to that flywheel.....

In neutral with the clutch out my truck rattles and makes a gringing like sound... this sound goes away when the clutch is pressed or if I raise the RPMs of the engine above 1200 or so.... I had heard that the SMF would give me a bit of gear clatter but it seems loud... any one with a SMF setup have input on what yours sounds like?

Cheers
Bob

 

I have a little rattle also until the pedal is pushed a bit. It seems with a hyd. system the throughout bearing always rides on the pressure plate.

 

.. I had heard that the SMF would give me a bit of gear clatter but it seems loud... any one with a SMF setup have input on what yours sounds like?

Cheers
Bob[/QUOTE]


Bob,

It would not suprize me if what you are hearing is due to the SMF, clutch, possibly the throw-out bearing riding. I read somewhere on the ZF site under troubleshooting that ZF went with the DMF to prevent transmission noises like you are describing.

That is always the trouble if you go custom like you have done, you risk endeding up with some funny noises like you have described. My advise is to keep an eye on it and see if it gets worse, or better yet if it goes away once things start to wear in a bit more.

It does not sound serious enought to tear everything apart again right away.

Good luck with it,


Seb.......

 

hamberger,

Have you found anything out about this sound? My truck is doing the same exact thing, (see my recent post).

Have you been driving this rig? Any issues? Any information woudl be great. Thanks!

 

I've heard that it is best to switch from ATF to straight 30 weight motor oil in the tranny after doing this swap - specifically to cut down on the gear rattle.....

 

I got 225kkm on my 93 and am running the original ZF5 with the original DMF, no problems or rattles. I changed the tranny oil at 160kkm, probably should have done it earlier.

Using motor oil might help the noise go down but this probably is not worth all the hassles you will get with the harder shifting due to the heavier oil.

Seb...

 

Man, this is deja-vu all over again! This is EXACTLY what happened to me last summer when I installed my ZF (for the first time). First, it was trouble with the clutch releasing. That turned out to be the clutch disk sticking to the pressure plate. Got that freed up and then discovered the noise you're describing. We're not talking a "little bearing rumble", or a "slight noise"; we're talking "scare you half to death, my tranny's about to explode" noise. I checked the oil level and tried a short road trip - gear/bearing noise in the first four gears whenever the clutch was engaged, NO noise in 5th. Man, I loved 5th! The difference in engine noise and RPM's is unbelievable! But the noise in neutral was pretty scary. I wound up pulling the trans back out and discovered that the 'correct' clutch disk was, in fact, 1/8" too large for the pp. Just enough that the initial interference wouldn't allow complete disengagement. Then after some 'in-place machining' the disk was still binding the input shaft and putting an axial load on the input shaft bearings. I reinstalled the 4spd, and plan on trying again later this month to reinstall the ZF.

I talked to Dave at Carolina Clutch, and he recommends the Luk flywheel/clutch set. He pointed out that there might be a difference between the height/thickness of the Luk smf flywheel and the stock smf flywheel. This would affect 'stack-up' and how the TOB works. (What Hamberger was talking about.) Installing all the stuff that's designed to work together will ensure that everything works as it's supposed to. Plus, pedal preessure is only about 15#. Very light.

Here's an option, if you don't mind going with an 11" clutch. Contack LMC truck parts (800.541.8425) and talk to them about kit #43-6845. It's for an 87 6.9 smf with the ZF 5spd. It's considerably cheaper than the Luk setup - $189.00 instead of $545. However, you'll have a smaller clutch and higher pedal pressure.

 

Thanks for that great summary on your experience Dave, much appreciated;

What you are going thru with your ZF clutch conversion is exactly what I always am afraid when you do a change like going from a DMF to SMF.

I have marked this thread for future reference when it comes time for my DMF rebuilt/replacement on my 93'.

If you really think about it you need to look at the entire clutch and tranny if you are going with a SMF replacement. It sounds like the guys from Luk thru good engineering and experience (probably more of the later) have managed to do this right)

Given how well my DMF has done for me it will be a difficult decision to switch to a SMF. The only argument for switching I would have is saving money. It takes two hands to count the number of times I have been burnt with trying to go cheap.

Good luck at your next attempt at the ZF5.



Seb.......

 

Thanks Seb. I've been kicking the choice around for a couple of months now. Going with the 'stock' clutch setup would save me about $350. And the 87 flywheel is probably identical to my 85 flywheel. However, I gotta tell ya, I'm really attracted to the sure bet. Having to pull that sucker out yet again because I guessed wrong is not something I want to do. Plus, I'm running short of time this Summer. I've got a three day window to get it done.

I've heard good things about the folks at Carolina Clutch. I trust Dave's suggestions; that's the way I'm gonna go.

 

I'm very interested in this. I was thinking of doing the DMF to SMF "conversion" and replacing the clutch disk & pressure plate. Of course I'd have had to have the converted DMF resurfaced as well. This looks like a much better option and probably less expensive too - as long as my SMF doesn't need resurfacing.....

I'm assuming that this will work just as well in an '86, and that the listing for it only shows the '87 because that was the only year that the ZF was available mated to the 6.9 from the factory. Can anyone confirm this and/or that it will/won't work in an 86?

 

I have done alot of the DMF to SMF several times. When I had my own shop I was doing about 2 a week for awhile. But that noise you guys are hearing is scary. My brother has a truck that does that and it has been doing it for about 2 years now. I took the trans apart and found nothing. It is loud. I think it is in the clutch set up causing it. It is strange. We figured what ever was causing it would scatter but it hasn't. It has gotton to be funny. You can hear that truck a 1/2 mile away.

 

Didja try putting something heavier than ATF in it?

 

We didn't but this noise is loud. I mean I live down the road about 300 yards and I can here it my house loud. It would probably help it from being so loud but I don't think it would "fix" it. If I hadn't heard it for myself I wouldn't have ever imagined that it was that loud or bad of a noise. When he called me and I went over to hear it I figured that something was left loose. He took the trans and clutch back out and didn't find a thing that looked wrong. It is an old work truck so we left it alone. Everybody is wanting to take bets on what part hits the ground first.

I am making light of this because it is a work truck but I feel for the guys on the forum. It is a head scratcher.

 

Well, for anyone else interested in this conversion using the 11" clutch, I have found that both Napa and PartsAmerica CKS (Checker/Schucks/Kragen) carry the same thing. The Napa one is about the same price, and the CKS is about 50 bucks cheaper. Here's the link to the one on the CKS site http://www.partsamerica.com/ProductD...pe=244&PTSet=A

The other advantages besides being about 50 bucks cheaper to start with are 1) no shipping charge - saving another 30 or 40 bucks AND 2) I can get warranty if needed at my local store - instead of by shipping it back and waiting for replacement.

Anybody have any experience with Fenco cluch sets? Good? Bad? Average?

 

Just quite a few of us that have that happen more than others. I call it an "expensive learning experiance"